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This commit is contained in:
Nikolaj Bjorner 2024-02-19 00:05:37 +07:00
parent 388b2f5eec
commit 046db662f9
9 changed files with 722 additions and 166 deletions
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64
src/ast/sls/bv_sls_terms.cpp
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@ -66,6 +66,7 @@ namespace bv {
};
unsigned num_args = a->get_num_args();
expr_ref r(m);
expr* x, * y;
#define FOLD_OP(oper) \
r = arg(0); \
for (unsigned i = 1; i < num_args; ++i)\
@ -98,6 +99,15 @@ namespace bv {
else if (bv.is_concat(e)) {
FOLD_OP(bv.mk_concat);
}
else if (bv.is_bv_sdiv(e, x, y) || bv.is_bv_sdiv0(e, x, y) || bv.is_bv_sdivi(e, x, y)) {
r = mk_sdiv(x, y);
}
else if (bv.is_bv_smod(e, x, y) || bv.is_bv_smod0(e, x, y) || bv.is_bv_smodi(e, x, y)) {
r = mk_smod(x, y);
}
else if (bv.is_bv_srem(e, x, y) || bv.is_bv_srem0(e, x, y) || bv.is_bv_sremi(e, x, y)) {
r = mk_srem(x, y);
}
else {
for (unsigned i = 0; i < num_args; ++i)
m_todo.push_back(arg(i));
@ -107,6 +117,60 @@ namespace bv {
m_translated.setx(e->get_id(), r);
}
expr* sls_terms::mk_sdiv(expr* x, expr* y) {
// d = udiv(abs(x), abs(y))
// y = 0, x > 0 -> 1
// y = 0, x <= 0 -> -1
// x = 0, y != 0 -> 0
// x > 0, y < 0 -> -d
// x < 0, y > 0 -> -d
// x > 0, y > 0 -> d
// x < 0, y < 0 -> d
unsigned sz = bv.get_bv_size(x);
rational N = rational::power_of_two(sz);
expr_ref z(bv.mk_zero(sz), m);
expr* signx = bv.mk_ule(bv.mk_numeral(N / 2, sz), x);
expr* signy = bv.mk_ule(bv.mk_numeral(N / 2, sz), y);
expr* absx = m.mk_ite(signx, bv.mk_bv_sub(bv.mk_numeral(N - 1, sz), x), x);
expr* absy = m.mk_ite(signy, bv.mk_bv_sub(bv.mk_numeral(N - 1, sz), y), y);
expr* d = bv.mk_bv_udiv(absx, absy);
expr* r = m.mk_ite(m.mk_eq(signx, signy), d, bv.mk_bv_neg(d));
r = m.mk_ite(m.mk_eq(z, y),
m.mk_ite(signx, bv.mk_numeral(N - 1, sz), bv.mk_one(sz)),
m.mk_ite(m.mk_eq(x, z), z, r));
return r;
}
expr* sls_terms::mk_smod(expr* x, expr* y) {
// u := umod(abs(x), abs(y))
// u = 0 -> 0
// y = 0 -> x
// x < 0, y < 0 -> -u
// x < 0, y >= 0 -> y - u
// x >= 0, y < 0 -> y + u
// x >= 0, y >= 0 -> u
unsigned sz = bv.get_bv_size(x);
expr_ref z(bv.mk_zero(sz), m);
expr_ref abs_x(m.mk_ite(bv.mk_sle(z, x), x, bv.mk_bv_neg(x)), m);
expr_ref abs_y(m.mk_ite(bv.mk_sle(z, y), y, bv.mk_bv_neg(y)), m);
expr_ref u(bv.mk_bv_urem(abs_x, abs_y), m);
return
m.mk_ite(m.mk_eq(u, z), z,
m.mk_ite(m.mk_eq(y, z), x,
m.mk_ite(m.mk_and(bv.mk_sle(z, x), bv.mk_sle(z, x)), u,
m.mk_ite(bv.mk_sle(z, x), bv.mk_bv_add(y, u),
m.mk_ite(bv.mk_sle(z, y), bv.mk_bv_sub(y, u), bv.mk_bv_neg(u))))));
}
expr* sls_terms::mk_srem(expr* x, expr* y) {
// y = 0 -> x
// else x - sdiv(x, y) * y
return
m.mk_ite(m.mk_eq(y, bv.mk_zero(bv.get_bv_size(x))),
x, bv.mk_bv_sub(x, bv.mk_bv_mul(y, mk_sdiv(x, y))));
}
void sls_terms::init() {
// populate terms